1. Field of the Invention
The present invention relates to an optical waveguide device including an optical waveguide and optical input and output ports for optically connecting a signal between electrical chips or the like within an electrical circuit substrate or a package, an optical and electronic elements combined device including the optical connection device and electrical circuits, a method of driving the optical and electrical elements combined device, and an electronic equipment using the optical and electrical elements combined device.
2. Related Background Art
In order to realize high performance of personal computers, mobile devices typified by cellular phones and PDAs (Personal Digital Assistants), digital AV (Audio Visual) apparatuses, and the like supporting the advanced information-oriented society, a large number of highly integrated LSI chips are used. Then, a mounting technique for operating the LSI chips integrated with high density at a high speed is required. However, the mounting technique using only a conventional electrical connection has reached the limit in solution of the problems of transmission delays and crosstalk, reduction of the EMI (Electromagnetic Interference), and the like. Thus, for the purpose of attaining the above-mentioned request, a system using an optical connection together with the conventional electrical connection has been examined.
Several examples of applying the optical connection to chips have been proposed. For example, it is disclosed in JP 8-293836 A that a slab type waveguide which is made of an organic polymer and which is formed on a flat substrate is used as a transmission medium. It is conceivable that this system has merits that the slab type waveguide has excellent matching with an LSI chip, or a board or a package having the LSI chip mounted thereto and is easy to be manufactured and also can be freely connected between chips as compared with a system for forming a line-shaped optical waveguide. An example of an optical connection device disclosed in JP 8-293836 A is shown in FIG. 11. In the device of FIG. 11, signal originating elements 204 and 206, and a signal receiving element 205 are provided on an insulating layer 208 of a substrate 201′ including an optical waveguide layer and encapsulated with a polymer encapsulation material 209, and an LSI board 202 is mounted thereto to thereby realize transmission of a signal between LSIs using a slab type optical waveguide 201″ (signal light 203). A hologram 207 is used for an optical coupling between the signal originating elements 204 and 206, and the signal receiving element 205, and the waveguide 201″. Moreover a wavelength controlling element controls a coupling state between the elements.
However, in the above-mentioned device disclosed in JP 8-293836 A as well, a signal light transmitted through a common waveguide does not always become a signal to be received by a predetermined light receiving element.